NAME
fstat
—
identify active files
SYNOPSIS
fstat |
[-fmnsv ] [-M
core] [-N
system] [-p
pid] [-u
user] [file ...] |
DESCRIPTION
Thefstat
utility identifies open files. A file is
considered open by a process if it was explicitly opened, is the working
directory, root directory, jail root directory, active executable text, or
kernel trace file for that process. If no options are specified,
fstat
reports on all open files in the system for
processes the user has access to.
The following options are available:
-f
- Restrict examination to files open in the same file systems as the named
file arguments, or to the file system containing the current directory if
there are no additional filename arguments. For example, to find all files
open in the file system where the directory
/usr/src resides, type
‘
fstat -f /usr/src
’. -M
core- Extract values associated with the name list from the specified core instead of the default /dev/kmem.
-m
- Include memory-mapped files in the listing; normally these are excluded due to the extra processing required.
-N
system- Extract the name list from the specified system instead of the default, which is the kernel image the system has booted from.
-n
- Numerical format. Print the device number (maj,min) of the file system the file resides in rather than the mount point name; for special files, print the device number that the special device refers to rather than the filename in /dev; and print the mode of the file in octal instead of symbolic form.
-p
pid- Report all files open by the specified process.
-s
- Print socket endpoint information.
-u
user- Report all files open by the specified user.
-v
- Verbose mode. Print error messages upon failures to locate particular
system data structures rather than silently ignoring them. Most of these
data structures are dynamically created or deleted and it is possible for
them to disappear while
fstat
is running. This is normal and unavoidable since the rest of the system is running whilefstat
itself is running. - file ...
- Restrict reports to the specified files.
The following fields are printed:
- USER
- The username of the owner of the process (effective uid).
- CMD
- The command name of the process.
- PID
- The process id.
- FD
- The file number in the per-process open file table or one of the following
special names:
If the file number is followed by an asterisk (‘
*
’), the file is not an inode, but rather a socket, FIFO, or there is an error. In this case the remainder of the line does not correspond to the remaining headers— the format of the line is described later under SOCKETS. - MOUNT
- If the
-n
flag was not specified, this header is present and is the pathname that the file system the file resides in is mounted on. - DEV
- If the
-n
flag is specified, this header is present and is the number of the device that this file resides in. - INUM
- The inode number of the file.
- MODE
- The mode of the file. If the
-n
flag is not specified, the mode is printed using a symbolic format (see strmode(3)); otherwise, the mode is printed as an octal number. - SZ|DV
- If the file is a semaphore, prints the current value of the semaphore. If
the file is not a character or block special, prints the size of the file
in bytes. Otherwise, if the
-n
flag is not specified, prints the name of the special file as located in /dev. If that cannot be located, or the-n
flag is specified, prints the major/minor device number that the special device refers to. - R/W
- This column describes the access mode that the file allows. The letter
‘
r
’ indicates open for reading; the letter ‘w
’ indicates open for writing. This field is useful when trying to find the processes that are preventing a file system from being down graded to read-only. - NAME
- If filename arguments are specified and the
-f
flag is not, then this field is present and is the name associated with the given file. Normally the name cannot be determined since there is no mapping from an open file back to the directory entry that was used to open that file. Also, since different directory entries may reference the same file (via ln(1)), the name printed may not be the actual name that the process originally used to open that file.
SOCKETS
The formatting of open sockets depends on the protocol domain. In all cases the first field is the domain name, the second field is the socket type (stream, dgram, etc.), and the third is the socket flags field (in hex). The remaining fields are protocol dependent. For TCP, it is the address of the tcpcb, and for UDP, the inpcb (socket pcb). For UNIX-domain sockets, its the address of the socket pcb and the address of the connected pcb (if connected). Otherwise the protocol number and address of the socket itself are printed.
For example, the addresses mentioned above are the addresses which
the ‘netstat -A
’ command would print
for TCP, UDP, and UNIX-domain. Note that since pipes are implemented using
sockets, a pipe appears as a connected UNIX-domain stream socket. A
unidirectional UNIX-domain socket indicates the direction of flow with an
arrow (‘<-
’ or
‘->
’), and a full duplex socket
shows a double arrow
(‘<->
’).
When the -s
flag is used, socket endpoint
information is shown after the address of the socket. For internet sockets
the local and remote addresses are shown, separated with a double arrow
(‘<->
’). For UNIX/local sockets
either the local or remote address is shown, depending on which one is
available.
EXIT STATUS
The fstat
utility exits 0 on
success, and >0 if an error occurs.
EXAMPLES
Show all open files except those opened by
fstat
itself:
$ fstat | awk '$2 != "fstat"' USER CMD PID FD MOUNT INUM MODE SZ|DV R/W alice bash 469 text /usr/local 143355 -rwxr-xr-x 1166448 r alice bash 469 ctty /dev 346 crw--w---- pts/81 rw ...
Report all files opened by the current shell in the same file system as /usr/local including memory-mapped files:
$ fstat -m -p $$ -f /usr/local USER CMD PID FD MOUNT INUM MODE SZ|DV R/W bob bash 469 text /usr/local 143355 -rwxr-xr-x 1166448 r bob bash 469 mmap /usr/local 143355 -rwxr-xr-x 1166448 r ...
Requesting information about a file that is not opened results in just a header line instead of an error:
$ fstat /etc/rc.conf USER CMD PID FD MOUNT INUM MODE SZ|DV R/W NAME
All parameters after -f
will be
interpreted as files, so the following will not work as expected:
$ fstat -f /usr/local -m -p $$ fstat: -m: No such file or directory fstat: -p: No such file or directory fstat: 469: No such file or directory ...
Show number of pipes opened by firefox processes:
$ fstat | awk '$2=="firefox" && $5=="pipe"' | wc -l
Show processes belonging to user “bob” whose standard error descriptor is opened in ttyv0:
$ fstat -u bob | awk '$4 == 2 && $8 == "ttyv0"' bob firefox 77842 2 /dev 103 crw------- ttyv0 rw bob xinit 1194 2 /dev 103 crw------- ttyv0 rw ...
Show opened TCP sockets. This output resembles the one produced by
‘netstat -A -p tcp
’ :
$ fstat | awk '$7 == "tcp"' alice firefox 77991 32* internet stream tcp fffff800b7f147a0 alice firefox 77991 137* internet stream tcp fffff800b7f12b70 ...
Show a list of processes with files opened in the current directory mimicking the output of fuser(1) :
$ fstat . | awk 'NR > 1 {printf "%d%s(%s) ", $3, $4, $1;}' 2133wd(alice) 2132wd(alice) 1991wd(alice)
Create a list of processes sorted by number of opened files in desdencing order:
$ fstat | awk 'NR > 1 {print $2;}' | sort | uniq -c | sort -r 728 firefox 23 bash 14 sort 8 fstat 7 awk
SEE ALSO
fuser(1), netstat(1), nfsstat(1), procstat(1), ps(1), sockstat(1), systat(1), tcp(4), unix(4), iostat(8), pstat(8), vmstat(8)
HISTORY
The fstat
command appeared in
4.3BSD-Tahoe.
BUGS
Since fstat
takes a snapshot of the
system, it is only correct for a very short period of time.